The programming is reasonably involved, especially if you want to code to a logic graphics interface, for portability reasons.

However, if you are willing to use a faster / cheaper chip, NXP offers emWin, completely free of charge and without any limitations, for its line of mcus. My experience with emWin (both on lpc and other chips) has been nothing but outstanding.

That 'machine' appears to be a vacuum tube tester? If so you might want to do a little research on it's market value as the audiophile people have bought into vacuum tube amps and pre-amps in a very big way, making the value of many of the old tube testers quite valuable. And the unit in the picture you posted seems like quite a piece of high end test equipment from a past era.

So yea, don't modify the unit until you find out if someone might want such a device and be willing to pay nicely for it. Is it functional?

Please. PLEASE!!! Do not ruin that beautiful vintage gear by jamming a digital meter into it. Have a little respect for the little beastie.

I suspect that your tube tester is not in the same condition as the one in the photograph but I wouldn't modify it in any case.

Do you have the original meter? Even if it is not working you might be able to salvage the meter face and body. The underlying mechanism is most likely a basic milliammeter and you could possibly fabricate a replacement meter by grafting an ordinary milliammeter to your original body.

This link --> http://frank.pocnet.net/instruments/AVO/MF/AVO_CT160A_Working_Instructions_and_Service_Manual_and_Inner_Workings-TIFF.pdf <-- has all kinds of information including the characteristics of the meter (it's actually a microammeter).

Or you could use a 4D Systems:http://www.4dsystems.com.au/products.php and look at the 3.2 PT and 4.3 PT serial displays. ave33 has a library for it listed somewhere here... The display is capable of some amazing things, SD card, Speaker 16 I/O organized as an 8 bit bi directional bus or 16 individual digt oital I/O, serial port in the display... The list of features is best read from the website...I own 2 of the 3.2 PT SGC modules and they work well.

Bob

--> WA7EMS "The solution of every problem is another problem." -Johann Wolfgang von GoetheI do answer technical questions PM'd to me with whatever is in my clipboard